Patient Tip Sheet on Anaphylaxis: Allergic Emergencies

Anaphylaxis is a rare, but potentially fatal allergic reaction that requires immediate attention and treatment. If you have a history of allergies and/or asthma and have had a severe reaction, you are at greater risk for anaphylaxis and education is one of the most important steps you can take to manage your condition.

The American College of Allergy, Asthma and Immunology (ACAAI) suggests the following tips:

1. Know your trigger.

If you’ve had anaphylaxis, it’s very important to know what triggered the reaction. An allergist can review your medical history and, if necessary, conduct diagnostic tests. The most common triggers are:

• Food including peanuts, tree nuts such as walnuts and pecans, fish, shellfish, cow’s milk and eggs.
• Latex, found in disposable gloves, intravenous tubes, syringes, adhesive tapes and catheters. Health care workers, children with spina bifida and genitourinary abnormalities and people who work with natural latex are at higher-risk for latex-induced anaphylaxis.
• Medication including penicillin, aspirin and non-steroidal anti-inflammatory drugs such as ibuprofen, and anesthesia.
• Insect sting, with bees, wasps, hornets, yellow jackets and fire ants being the most likely to trigger anaphylaxis.

2. Avoid your trigger.

Avoidance is the most effective way to prevent anaphylaxis. An allergist can work with you to develop specific avoidance measures tailored specifically for your age, activities, occupation, hobbies, home environment and access to medical care. Here are some general avoidance techniques for common triggers:

• Food allergies. Be a label detective and make sure you review all food ingredient labels carefully to uncover potential allergens. When eating out, ask the restaurant how food is prepared and what ingredients are used. If you have a child with a history of anaphylaxis, it’s imperative to make sure that school personnel are informed of the child’s condition and a treatment plan is provided, including the administration of epinephrine.
• Latex. Before having any medical-surgical-dental procedure, it’s important to inform your doctor about your condition and make sure that the procedure is performed in a latex-safe environment. If possible, request that you be the first procedure for the day to further limit possible exposure. Health care workers who have a latex allergy should wear non-latex and powder-free gloves and have colleagues do the same.
• Medications. Make sure all of your doctors are aware of any reactions you’ve had to medications so that they can prescribe safe alternatives and alert you to other medications you may need to avoid. If there are no alternative medications, you may be a candidate for desensitization, a treatment that introduces a small dose of the medication you are allergic to. As your body becomes more tolerant to the medication, the dosage can be increased over time. While the treatment is effective, it’s only temporary and must be repeated if the medication is needed again in the future.
• Insect stings. To help prevent stinging insects, avoid walking barefoot in grass, drinking from open soft drink cans, wearing bright colored clothing with flowery patterns, sweet smelling perfumes, hairsprays and lotion during active insect season in late summer and early fall. An allergist can also provide a preventive treatment called venom immunotherapy (or venom allergy shots) for insect sting allergy. The treatment works by introducing gradually increasing doses of purified insect venom, and has been shown to be 90 percent to 98 percent effective in preventing future allergic reactions to insect stings.

3. Be prepared.

Prompt recognition of the signs and symptoms of anaphylaxis is critical. If you unexpectedly come into contact with your trigger, you should immediately follow the emergency plan outlined by your doctor including the self-administration of epinephrine. If there is any doubt about the reaction, it is generally better to administer the epinephrine.

4. Seek treatment.

If a severe reaction does occur and epinephrine is administered, you should be transported to the nearest emergency facility by ambulance for additional monitoring.

5. Tell family and friends.

Family and friends should be aware of your condition, your triggers and know how to recognize anaphylactic symptoms. If you carry epinephrine, alert them to where you keep it and how to use it.

6. Wear identification.

Wear and/or carry identification or jewelry (Medic Alert bracelet or necklace) noting condition and offending allergens. Medic Alert (888-633-4298 or www.medicalert.org ) provides identification and medical information in emergencies and includes a 24-hour emergency response service.

7. See a specialist.

Allergists have the training and expertise to review your allergy history, conduct diagnostic tests, review treatment options and teach avoidance steps. Consultation with a specialist is recommended if you:

• Are unsure if you have had anaphylaxis
• Experience recurring symptoms or symptoms that are difficult to control
• Need additional assistance in managing your condition
• Require additional tests to determine the cause of your reactions
• Are a candidate for desensitization or immunotherapy
• Require daily medication
• Need intensive education on avoidance and management
• Have other conditions that complicate your anaphylaxis and its treatment

Drug Reactions

Most people have probably experienced an unwanted side effect to a medicine at some time in their lives. Many drugs commonly cause side effects, such as an upset stomach after taking aspirin or drowsiness after taking a cold medication. Adverse drug reactions also can be quite serious; they account for an estimated 106,000 deaths each year in the United States. As more medications are approved each year, the problem is expected to grow.

An adverse drug reaction is any effect not intended by proper administration of a medication. Reactions also can occur between medications, even nonprescription ones. Most adverse drug reactions – more than 90 percent – do not involve the immune system. When the immune system is involved, a person is said to have drug hypersensitivity. Allergy is one type of hypersensitivity reaction.

What is drug hypersensitivity?

Medications can cause unwanted reactions in many ways. Sometimes, it’s a direct effect of the drug on the body. Drug hypersensitivity reactions occur when the immune system responds to a medication or to the biologic products that result when the body breaks down a medication. In some cases, the immune system tries to attack the substance, causing symptoms of the drug reaction. Drugs also can cause allergic reactions similar to those caused by bee stings or other allergenic substances.

People who have a family history of allergic diseases may be more likely to have drug allergy, but are not at greater risk to develop non-allergic types of reactions. Fortunately, a family history of allergy to a particular drug does not increase a person’s chance of being allergic to that same drug.

A person must have a previous exposure to a drug in order to have a true allergic reaction to it. Such reactions most often occur when a drug is administered intravenously or by injection, delivery methods that send the drug directly to the bloodstream. Reactions occur less frequently when drugs are taken by mouth. The chance of an allergic reaction increases when a medication is administered frequently or in large doses.

Certain medications are more likely to cause allergic reactions than others due to their chemical structure. Penicillin and other antibiotics are some of the most common culprits of allergic drug reactions. Penicillin, however, can also cause other types of immune reactions, as well as reactions that do not involve the immune system.

Symptoms

The most common types of allergic reactions to a drug are:

• Skin rash or hives
• Itchy skin
• Wheezing or other breathing problems
• Swelling of body parts
• Anaphylaxis, a life-threatening allergic reaction

While these are the most common symptoms of drug allergy, adverse reactions can occur in any organ or system of the body.

Allergic reactions can occur within minutes or hours of exposure to a medication. Drug reactions can even occur some time after a medication has been stopped. For example, a person may develop a rash or hives a week after stopping a medication.

A “pseudoallergic,” or anaphylactoid, reaction does not involve allergic antibodies and can occur without prior exposure. Symptoms are similar to a true allergic reaction: a person may develop a rash or hives, have difficulty breathing, and experience swelling of body parts. Common causes of pseudoallergic reactions include aspirin and X-ray dye.

Diagnosis

Adverse drug reactions can be difficult to diagnose, because they often can look like other conditions. Further, although many common reactions to certain drugs are known, others may not have been identified yet.

It is important to distinguish an allergic (hypersensitivity) reaction from a non-allergic reaction. If drug hypersensitivity is suspected, your doctor may send you to a specialist in allergy and immunology.

If you suspect you are having, or had, an adverse reaction to a medication, take note of the circumstances. Your doctor will want to know when the medication was taken, when the symptoms started, what the symptoms were and how long they lasted, and any other medications you were taking at the time, including nonprescription medications. Bring copies of any treatment records of the reaction with you to the doctor’s office. This information is important for the diagnosis and treatment of your condition.

Be sure to have the name of the exact medications you took to help the doctor identify which drugs should be tested for hypersensitivity. It also will allow the allergist to determine if there are alternative medications that would be safe for you to take – and which additional medications you should avoid in the future. If possible, bring the suspected medications with you.

Next, an allergist will perform a physical examination. This is necessary to check for different problems that may occur as part of an allergic reaction and to determine if there are other, non-allergic causes of the symptoms. The allergist will pay special attention to any symptoms of a reaction that you still have, such as a skin rash.

Allergy skin testing is available to test for allergic reactions to only a few drugs. Many experts recommend that testing not be done until there is a future, compelling need to use the same medication again. In some cases, an allergist will perform blood tests to identify antibodies against a medication. Blood tests tend to be less sensitive than skin tests, so a skin test will be used whenever possible.

Treatment

If a drug reaction is mild, treatment may be limited to stopping the medication. In many cases, discontinuing the drug is all that is needed.

To relieve the symptoms of a more serious or persistent reaction, an allergist may administer antihistamines, corticosteroids and other medications. Antihistamines work by counteracting the chemical histamine, which is released during the body’s allergic response. Corticosteroids work by reducing inflammation.

In most cases, a person with drug hypersensitivity can safely be given alternative drugs, and the drug that caused the reaction is simply avoided. When no alternative medication exists, an allergist can undertake desensitization or graded challenge. These are methods of gradually introducing a medication into the body in small doses until a therapeutic dose is reached.

If you have a known drug allergy

If you have had a hypersensitivity reaction to a drug:

• Make sure all of your doctors know the medication you took and the reaction you had;
• Talk to your primary care doctor or allergist about other medications you should avoid and which alternative medications are safe for you to take; and
• If your allergy is severe, wear a medical alert tag or bracelet in case of emergency.